<template>
  <div class="container_box">
    <div
      class="verify-character"
      :style="{ width: `${contentWidth}px;` }"
      @click="verifyRefresh"
    >
      <canvas
        class="canvas_character"
        ref="canvas_character"
        :width="contentWidth"
        :height="contentHeight"
        @click="getResult"
      >
      </canvas>
    </div>
  </div>
</template>
<script>
export default {
  props: {
    contentWidth: {
      type: Number,
      default: 112,
    },
    contentHeight: {
      type: Number,
      default: 38,
    },
  },
  components: {},
  data() {
    return {
      show_num: [],
    };
  },
  methods: {
    // 绘制图形码
    drawPic(show_num) {
      let canvas_width = this.contentWidth;
      let canvas_height = this.contentHeight;
      let canvas = this.$refs["canvas_character"]; //获取到canvas的对象，演员
      let context = canvas.getContext("2d"); //获取到canvas画图的环境，演员表演的舞台
      canvas.width = canvas_width;
      canvas.height = canvas_height;
      let sCode =
        "a,b,c,d,e,f,g,h,i,j,k,m,n,p,q,r,s,t,u,v,w,x,y,z,A,B,C,E,F,G,H,J,K,L,M,N,P,Q,R,S,T,W,X,Y,Z,1,2,3,4,5,6,7,8,9,0";
      let aCode = sCode.split(",");
      let aLength = aCode.length; //获取到数组的长度

      for (let i = 0; i < 4; i++) {
        //这里的for循环可以控制验证码位数（如果想显示6位数，4改成6即可）
        let j = Math.floor(Math.random() * aLength); //获取到随机的索引值
        // var deg = Math.random() * 30 * Math.PI / 180;//产生0~30之间的随机弧度
        let deg = Math.random() - 0.5; //产生一个随机弧度
        let txt = aCode[j]; //得到随机的一个内容
        // this.show_num[i] = txt.toLowerCase();
        show_num[i] = txt;
        let x = canvas_height + i * 25; //文字在canvas上的x坐标
        let y = 36 + Math.random() * 8; //文字在canvas上的y坐标
        context.font = "bold 23px 微软雅黑";
        context.clearRect(x, y, canvas_width, canvas_height); // 清空之前绘制的矩形,释放空间
        context.fillStyle = this.randomColor(0, 255, 0.1); // 填充颜色
        context.fillRect(0, 0, canvas_width, canvas_height); // 绘制矩形
        context.translate(x, y);
        context.rotate(deg);

        context.fillStyle = this.randomColor(0, 255, 1);
        context.fillText(txt, 0, 0);

        context.rotate(-deg);
        context.translate(-x, -y);
      }
      for (let i = 0; i <= 5; i++) {
        //验证码上显示线条
        context.strokeStyle = this.randomColor(0, 255, 1);
        context.beginPath();
        context.moveTo(
          Math.random() * canvas_width,
          Math.random() * canvas_height
        );
        context.lineTo(
          Math.random() * canvas_width,
          Math.random() * canvas_height
        );
        context.stroke();
      }
      for (let i = 0; i <= 30; i++) {
        //验证码上显示小点
        context.strokeStyle = this.randomColor(0, 255, 1);
        context.beginPath();
        let x = Math.random() * canvas_width;
        let y = Math.random() * canvas_height;
        context.moveTo(x, y);
        context.lineTo(x + 1, y + 1);
        context.stroke();
      }
      this.getResult();
    },

    // 随机颜色
    randomColor(min, max, Alpha) {
      let r = this.randomNum(min, max);
      let g = this.randomNum(min, max);
      let b = this.randomNum(min, max);
      return "rgba(" + r + "," + g + "," + b + "," + Alpha + ")";
    },
    // 随机数
    randomNum(min, max) {
      return Math.floor(Math.random() * (max - min) + min);
    },
    // 获取结果
    getResult() {
      this.result = this.show_num.join(" ");
      this.$emit("retrunResult", this.result);
    },
    // 刷新
    verifyRefresh() {
      this.drawPic(this.show_num);
    },
  },
  mounted() {
    this.drawPic(this.show_num);
  },
  watch: {},
  computed: {},
  filters: {},
};
</script>
<style lang="scss" scoped></style>
